[PATCH v2 1/2] libnvdimm/badrange: remove two redundant list_empty() branches

From: Zhen Lei
Date: Sat Sep 19 2020 - 06:46:55 EST


In add_badrange() or badblocks_populate(), the list_empty() branch does
the same things as the code after list_for_each_entry().

The pseudo code is as follows:
1) if (list_empty()) {
do things-A
return Y;
}

2) list_for_each_entry()
do things-B //can only be entered if !list_empty()

3) do things-A
return Y;

It's very clear that, the processing result after deleting 1) is the same
as that before deleting 1).

So delete 1) to simplify code.

Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
---
drivers/nvdimm/badrange.c | 10 ----------
1 file changed, 10 deletions(-)

diff --git a/drivers/nvdimm/badrange.c b/drivers/nvdimm/badrange.c
index b9eeefa27e3a507..9fdba8c43e8605e 100644
--- a/drivers/nvdimm/badrange.c
+++ b/drivers/nvdimm/badrange.c
@@ -53,13 +53,6 @@ static int add_badrange(struct badrange *badrange, u64 addr, u64 length)
bre_new = kzalloc(sizeof(*bre_new), GFP_KERNEL);
spin_lock(&badrange->lock);

- if (list_empty(&badrange->list)) {
- if (!bre_new)
- return -ENOMEM;
- append_badrange_entry(badrange, bre_new, addr, length);
- return 0;
- }
-
/*
* There is a chance this is a duplicate, check for those first.
* This will be the common case as ARS_STATUS returns all known
@@ -215,9 +208,6 @@ static void badblocks_populate(struct badrange *badrange,
{
struct badrange_entry *bre;

- if (list_empty(&badrange->list))
- return;
-
list_for_each_entry(bre, &badrange->list, list) {
u64 bre_end = bre->start + bre->length - 1;

--
1.8.3